1. Field of the Invention
The present invention relates to a network connection apparatus for connecting a plurality of network terminals to an external network such as the Internet.
2. Description of the Related Art
Recently, along with the rapid spread of the Internet, there is a mounting need for connecting plural personal computers (PCs) at home or in small office to the Internet in batch.
FIG. 22 is a block diagram of a conventional network system, assuming a small office. Operation of the conventional network system when a PC 304a sends an electronic mail (E-mail) to outside is explained. The E-mail from the PC 304a is transmitted to the Internet 301 through a router 302. At this time, if a PC 304b attempts to access the Internet, transmission is allowed when Ethernet 303, a transmission line, is free. However, while the line is busy as being used by the PC 304a, it is required to wait until free. When it is confirmed that the line is free, access to the Internet, an external network, is started.
Herein, information is transmitted and received by the so-called CSMA/CD (carrier sense multiple access/collision detect) system.
The clients, PC304a, 304b, 304c, can access the Internet at the same time, but the transmission speed is slower than when one unit accesses.
On the other hand, at home, plural information appliances such as AV apparatus, telephone, and facsimile equipment are used independently, and they are desired to be combined into a network.
However, in particular, if attempted to centralize plural PCs at home and connect to an external network, it is difficult to connect Ethernet wiring at home, and an easier and more flexible network system is needed.